This invention relates to a recording and/or reproducing apparatus for use in combination with a disc cartridge containing a magneto optical disc.
A typical type of the conventional disc drive is composed substantially of a base plate on which mechanisms, including a pick-up device and a spindle required for the recording/reproducing operation, a sliding plate attached slidably to the base plate and a loading chassis for accommodating a disc cartridge. The loading chassis is moveable in a vertical direction between an operative position wherein it is located near the base plate to be ready for the recording/reproducing operation and a standby position wherein it is retracted from the base plate. The loading chassis ascends along with advancement of the sliding plate in the cartridge ejecting operation and, in turn, descends along with insertion of the disc cartridge into the loading chassis. More particularly, as the sliding plate is advanced against a biasing force of a spring connected thereto, the loading chassis which has been standing in the lower operative position is elevated toward the upper standby position due to engagement between guide rollers protruded outwardly from opposite sides of loading chassis and upwardly inclined cam ridges of walls upstanding from opposite sides of sliding plate. There is also provided means for retaining the sliding plate in the fully-advanced position which causes the loading chassis to remain stationery in the standby position. Such locked condition of the sliding plate is released when the disc cartridge is inserted to the loading chassis which has been held in the standby position, whereupon the sliding plate is sprung back toward the cartridge unloading direction to thereby descend the loading chassis toward the lower operative position.
With the disc drive used for a disc cartridge containing a magneto optical disc, a bias magnet is arranged in a position opposite to the pick-up mechanism for applying a bias magnetic field to recording area of the disc at a time of recording. The bias magnet should be positioned to leave a predetermined small interval, of the order of 1.sub.mm, between its magnetic pole section and the disc face, which would be obstructive to the cartridge insertion into a space defined between the bias magnet and the pick-up mechanism.